RHBDF1 and cancer: Despite the lack of protease activity, the RHBDF1 protein has been found to participate critically in many important biological processes, including stabilizing hypoxia-inducible factor-1α (HIF-1α) in cancer cells under hypoxic conditions[14] and promoting activator protein 1 (AP-1)-activated endothelial-mesenchymal transition (EndMT) by activating the c-Jun N-terminal kinase (JNK) pathway[15].